Cam-type pump structure for a refrigerant recycling machine

ABSTRACT

A cam-type pump structure for a refrigerant recycling machine includes a cam device driven by a motor for pistons to be reciprocated in conjunction with cylinders and valve bodies so as to pump liquid. The pump apparatus is compact in size and has high efficiency for the demand of recycling refrigerant.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cam-type pump structure for a refrigerant recycling machine. In particular, a pump apparatus uses a cam-type structure for pistons to be reciprocated in the same direction or in opposite directions so as to pump refrigerant.

2. Description of the Prior Art

Refrigerant is widely used in our daily living, such as domestic refrigerators, air conditioners, refrigerating equipment or car air conditioners. When refrigerators or air conditioners need maintenance, it is required to drain out the refrigerant. This not only pollutes the ambient air but also brings poisonous substances to harm the human body when the refrigerant is burned at a high temperature. Recently, there is a refrigerant recycling machine on the market to pump the refrigerant or the like into a specific container, which conforms to the operation safety and protects the global environment.

The existing refrigerant recycling machine doesn't have a proper design for its inside construction. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to improve the existing products.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide a cam-type pump structure for a refrigerant recycling machine, which comprises two pairs of pistons and cylinders. The two pistons are driven by a cam device. When the cam device is activated, the two pistons are reciprocated synchronously. The pistons are reciprocated in the same direction or in opposite directions. By the motion of the pistons, the present invention provides a high efficiency and is compact in size.

In order to achieve the object, the present invention comprises a main body. The main body comprises a motor at one end thereof. The motor has an output end which is a shaft. The main body has a space therein. The shaft of the motor is disposed in the space. A cam device is inserted on the shaft. The cam device comprises a central rotating body and two eccentric rotating bodies at two sides of the central rotating body. A bearing is provided at an outer end of each of the eccentric rotating bodies. An outer sleeve is provided at an outer end of the bearing. The outer sleeve has a protrusion at one end thereof and a piston at a distal end of the protrusion. The main body has a pair of openings at two sides thereof. Each opening is connected with a cylinder. The cylinder has a chamber therein to receive the piston for reciprocation.

Preferably, a fan is provided at an outer end of the motor to lower the temperature and dissipate the heat when in operation.

Preferably, the main body has a ring portion at an outer edge of the space. The ring portion is covered with a plate to seal the space.

Preferably, each cylinder is connected with a valve body. The inside of the cylinder communicates with the inside of the valve body. The valve body has an inlet and an outlet. The piston is reciprocated in the cylinder to form pressure for the valve body to provide a pump function.

Preferably, the center of the central rotating body of the cam device is formed with an axial hole for insertion of the shaft of the motor. The axial hole penetrates each eccentric rotating body and isn't located at the center of each eccentric rotating body.

Preferably, the centers of the two eccentric rotating bodies are located at different axes. When the shaft is turned to drive the central rotating body, the two eccentric rotating bodies will be turned eccentrically at different angles and the two pistons at the two sides of the cam device will be reciprocated in opposite directions. In this way, the two valve bodies are to pump synchronously, providing a better pump function.

Alternatively, the centers of the two eccentric rotating bodies are located at the same axis. When the shaft is turned to drive the central rotating body, the two eccentric rotating bodies will be turned eccentrically at the same angle and the two pistons at the two sides of the cam device are reciprocated in the same direction. In this way, the two valve bodies are to pump in turn, providing a smooth operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the present invention;

FIG. 2 is an exploded view of the present invention;

FIG. 3 is an exploded view of a cam device of the present invention;

FIG. 4 is a cross-sectional showing the cam device of the present invention in an operating status;

FIG. 5 is another cross-sectional showing the cam device of the present invention in an operating status;

FIG. 6 is an exploded view of a cam device according to another embodiment of the present invention; and

FIG. 7 is a cross-sectional view of FIG. 6 showing the cam device of the present invention in an operating status.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.

As shown in FIGS. 1 to 4, a cam-type pump structure for a refrigerant recycling machine according to a first preferred embodiment of the present invention comprises a main body 1, a cam device 2, a cylinder 3 and a valve body 4.

The main body 1 has a casing shape and comprises a motor 11 at one end thereof. A fan 12 is provided at an outer side of the motor 11. The motor 11 has an output end which is a shaft 14. The main body 1 has a space 13 therein. The shaft 14 of the motor 11 is disposed in the space 13. The cam device 2 is inserted on the shaft 14. A distal end of the shaft 14 is provided with a shaft bearing 141. The main body 1 has a pair of openings 15 at two sides thereof to receive the cylinder 3. The main body 1 has a ring portion 16 at an outer edge of the space 13. The main body 1 further comprises a plate 17 and a rubber washer 171 associated with an oil seal ring 161 to seal the space 13. The plate 17 and the rubber washer 171 are connected to the ring portion 16 with screws 172.

The cam device 2 comprises a central rotating body 21, a pair of eccentric rotating bodies 22 at two sides of the central rotating body 21, a pair of bearings 24 next to the pair of eccentric rotating bodies 22 and a pair of outer sleeves 25 next to the pair of the bearings 24. Each outer sleeve 25 has a protrusion 26 at one end thereof and a piston 27 at a distal end of the protrusion 26. The cam device 2 has an axial hole 23 along a central axis thereof. In this embodiment, the axial hole 23 penetrates through the center of the central rotating body 21, but not through the center of each eccentric rotating body 22.

The cylinder 3 is coupled to the opening 15 of the main body 1. The cylinder 3 has a chamber 31 therein to receive the piston 27 for reciprocating motion. Preferably, there are two openings 15 in this embodiment, so the cylinder 3 corresponds in number to the opening 15.

The valve body 4 is mounted on the cylinder 3. The inside of the cylinder 3 communicates with the inside of the valve body 4. The valve body 4 has an inlet 41 and an outlet 42. The piston 27 is reciprocated in the cylinder 3 to form pressure for the valve body 4 to provide a pump function.

When the motor 11 is started, the shaft 14 will be driven to turn the cam device 2 on the shaft 14. The central rotating body 21 and the two eccentric rotating bodies 22 are turned synchronously. Because the axial hole 23 is not disposed at the center of each eccentric rotating body 22, the cam device 2 is turned eccentrically. As shown in FIG. 4 and FIG. 5, the two eccentric rotating bodies 22 are in an eccentric motion, and the two pistons 27 at the two sides of the cam device 2 are reciprocated in opposite directions, namely, they are synchronously turned inward or outward, such that the two valve bodies 4 are to pump synchronously. In this motion way, the two valve bodies 4 provide more efficiency to pump than a single piston with a single valve.

FIG. 6 shows a second embodiment of the present invention, which is substantially similar to the first embodiment with the exceptions described hereinafter. A cam device 5 comprises a central rotating body 51, a pair of eccentric rotating bodies 52 at two sides of the central rotating body 51, a pair of bearings 54 next to the pair of eccentric rotating bodies 52 and a pair of outer sleeves 55 next to the pair of the bearings 54. Each outer sleeve 55 has a protrusion 56 at one end thereof and a piston 57 at a distal end of the protrusion 56. The cam device 5 has an axial hole 53 along a central axis thereof. In this embodiment, the axial hole 53 penetrates through the center of the central rotating body 51, but not through the center of each eccentric rotating body 52. In particular, the centers of the two eccentric rotating bodies 52 are located at the same axis, namely, the two eccentric rotating bodies 52 are eccentric toward the same side relative to the axial hole 53 simultaneously. In addition, the central rotating body 51 has an engaging groove 511 on one side thereof and a threaded hole 512 in the engaging groove 511. The engaging groove 511 is adapted to receive a rib 581 of a counterweight block 58. The counterweight block 58 has a hole 582 thereon for insertion of a screw 583, such that the counterweight block 58 is coupled to the central rotating body 51. Because the two eccentric rotating bodies 52 are eccentric toward the same side relative to the axial hole 53 simultaneously, the two eccentric rotating bodies 52 will be turned eccentrically when the shaft 14 is turned. In order to solve this problem, in this embodiment the counterweight block 58 is located at an opposite side relative to the eccentric rotating bodies 52 for balance.

When the motor 11 is started, the shaft 14 will be driven to turn the cam device 5 on the shaft 14. The central rotating body 51 and the two eccentric rotating bodies 52 are turned synchronously. Because the axial hole 53 is not disposed at the center of each eccentric rotating body 52, the cam device 5 is turned eccentrically. As shown in FIG. 7, the centers of the two eccentric rotating bodies 52 are located at the same axis, and the two pistons 57 at the two sides of the cam device 5 are reciprocated in the same direction, namely, one piston 57 is turned inward and the other piston 57 is turned outward, such that the two valve bodies 4 are to pump in turn. In this motion way, the motion directions of the cam device 5 and the piston 57 are the same, providing a smooth operation.

Although particular embodiments of the present invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be limited except as by the appended claims. 

1. A cam-type pump structure for a refrigerant recycling machine, comprising a main body, a cam device and a cylinder; the main body comprising a motor, the motor having an output end provided with a shaft, the main body having a space therein, the shaft of the motor being disposed in the space, the cam device being inserted on the shaft, the main body having an opening at one side thereof; the cam device comprising a central rotating body and two eccentric rotating bodies, each of the two eccentric rotating bodies being connected with a piston, the cam device having an axial hole along a central axis thereof, the shaft being inserted through the axial hole and the eccentric rotating bodies; and the cylinder being coupled to the opening of the main body, the cylinder having a chamber therein to receive the piston for reciprocation.
 2. The cam-type pump structure for a refrigerant recycling machine as claimed in claim 1, wherein the main body has a casing shape, a fan being provided at an outer side of the motor, the main body having a ring portion at an outer edge of the space, the main body further comprising a plate and a rubber washer associated with an oil seal ring to seal the space, the plate and the rubber washer being connected to the ring portion with screws.
 3. The cam-type pump structure for a refrigerant recycling machine as claimed in claim 1, wherein a distal end of the shaft is provided with a shaft bearing.
 4. The cam-type pump structure for a refrigerant recycling machine as claimed in claim 1, wherein the two eccentric rotating bodies of the cam device are located at two sides of the central rotating body.
 5. The cam-type pump structure for a refrigerant recycling machine as claimed in claim 1, wherein a bearing is provided at an outer end of each of the eccentric rotating bodies, an outer sleeve being provided at an outer end of the bearing, the outer sleeve having a protrusion at one end thereof, the piston being located at a distal end of the protrusion.
 6. The cam-type pump structure for a refrigerant recycling machine as claimed in claim 1, wherein the axial hole is located at the center of the central rotating body.
 7. The cam-type pump structure for a refrigerant recycling machine as claimed in claim 1, wherein the cylinder is connected with a valve body, the inside of the cylinder communicating with the inside of the valve body, the valve body having an inlet and an outlet.
 8. The cam-type pump structure for a refrigerant recycling machine as claimed in claim 1, wherein the centers of the two eccentric rotating bodies are located at different axes.
 9. The cam-type pump structure for a refrigerant recycling machine as claimed in claim 1, wherein the centers of the two eccentric rotating bodies are located at the same axis.
 10. The cam-type pump structure for a refrigerant recycling machine as claimed in claim 9, wherein one side of the central rotating body is provided with a counterweight block, the counterweight block being located at an opposite side relative to the eccentric rotating bodies for balance, the side of the central rotating body having an engaging groove and a threaded hole in the engaging groove, the engaging groove being adapted to receive a rib of the counterweight block, the counterweight block having a hole thereon for insertion of a screw so that the counterweight block is coupled to the central rotating body. 